There are simplified depreciation rules and claim of an immediate deduction for the business portion of new or second hand asset costing less than $20,000 if:
a) a business have a turnover less than $10 million (increased from $2 million on 1 July 2016), and
 b) the asset was first used or installed ready for use in the income year a business is claiming it in.
The $20,000 threshold applied from 12 May 2015 and will reduce to $1,000 from 1 July 2018.
In the latest Federal Budget, there is a proposal to extend the $20,000 instant asset write-off threshold to 30 June 2019. This change is not law yet.